Properties alone do not choose a material. These sourced guides connect alloy history, temper processing, specifications, machining behavior, and applications to the forms you can actually buy.
5 sourced guides
6061-T651 is 6061 aluminum that has been solution heat treated, stress relieved by controlled stretching, and then artificially aged to the T6 strength level. The added stress-relief step is why T651 plate is normally preferred over plain T6 for machined parts that must remain flat after substantial material removal.
6061-T6511 is an extruded 6061 product that has been solution heat treated, stress relieved by stretching, artificially aged, and allowed minor straightening after stretching. It is the familiar condition for 6061 round and flat bar because it combines T6-level strength with improved machining stability and commercial straightness.
7075-T651 is high-strength 7075 aluminum plate in a T6-type peak-aged condition, with residual stress reduced by stretching. It offers one of the highest strength-to-weight ratios among commonly stocked aluminum plates, but its corrosion, stress-corrosion, forming, and welding limits require more deliberate design choices than 6061.
7075-T7351 is stretched 7075 plate that is overaged to improve resistance to stress-corrosion cracking. It gives up some of the peak strength of 7075-T651 in exchange for better durability under sustained stress in demanding environments, making it a deliberate engineering choice rather than a lower-grade substitute.
7050-T7451 is high-strength aerospace plate engineered for thick sections where toughness, through-thickness properties, and stress-corrosion resistance matter. It is solution heat treated, stretched to reduce residual stress, and overaged, and it is commonly specified to AMS 4050 for large machined structural parts.
4 sourced guides
304/304L annealed round bar is the general-purpose austenitic stainless bar used for shafts, pins, fittings, food equipment, and chemical hardware. Chromium and nickel create its corrosion-resistant, ductile structure; the low-carbon 304L side of a dual certification improves welded-service resistance to sensitization.
316/316L annealed round bar is an austenitic stainless with molybdenum added to improve resistance to chloride pitting and crevice corrosion compared with 304. It is a common choice for marine, pharmaceutical, food, chemical, and water-service parts, while 316L controls carbon for welded applications.
17-4 PH Condition A round bar is UNS S17400 stainless in the solution-treated condition supplied before final precipitation aging. Shops often machine it in Condition A, then apply an approved H900-through-H1150 aging cycle to reach the strength, hardness, toughness, and corrosion balance required by the drawing.
416 annealed round bar is a sulfur-modified martensitic stainless designed for high machining rates and good chip control. It is commonly turned into shafts, fasteners, fittings, and precision components, but the sulfur that improves machinability also reduces corrosion resistance, weldability, and transverse toughness compared with less free-machining stainless grades.
Use the guide to narrow the choice, then put the controlling standard and revision on the purchase order. The mill cert—not a web page—is the acceptance record for a delivered heat.
